Dubstep allstars Vol.03, mixed by Kode9 and hosted by The Spaceape, is the dubstep mix CD re-imagined.

Armed with a mic and the same 10" dubplate weapons, but approaching from a completely different trajectory, this is a creation greater than the sum of its parts. Observe how the line gets twisted out of all recognition.

First there's the slection, a crucial element in any DJs arsenal. This defines the range of emotional spaces likely to be encountered along the way. For this mix, Kode9 drew from his London surroundings, taking South London dubstep and East London grime and heading into uncharted waste ground.

The majority of the material is unreleased; fresh and upfront, it's carefully selected for its strength and potential. The effect of this is twofold. It ensures the listener is receiving the very latest sounds, the very edge of the expanding dubstep sphere as defined by the collective imagination of a self-sustaining musical community. The second effect is internal: by selecting the best tracks that fit his vision, and not simply big tracks from the most established names, it feeds back creative energy into the very community from which they are drawn by suggeting a production meritocracy

Given the six year history of dubstep, this is key. Evolving out of an unsympathetic early '00s 2-step garage scene, the dubstep community has been built by the collective efforts of commited and determined individuals, without the support of major label or other financially lucrative scenes. And within that community reward and recognition are essential for long term growth.

His selection made, Kode9 then cut them to dubplate. Not out of historical reverence or status statement but out of love for the medium's inherent properties. Responsive and tactile, dubplates allow a DJ who wants to shape a nebulous selection of unreleased music into a coherent whole. Scraped, nudged and blended together on dubplate, individual tracks blur, while pitches and tempo interact with each other to produce new tones, keys and cadences.

While most electronic production equipment encourages composition in fixed keys or intervals, DJing makes a mockery of this. Within the +/- 8% pitch range of most decks there are an infinite number of tonal subdivisions. Beat matching a given pair of dubplates often means abandoning one or both of the original tempos, and as a consequence, the original keys or tones. The mix is thus volatile and singular, not least because it's also encoded with a unique background of decaying pops and micro-crackles from the dubplate's fading surface.

But the mix is yet more volatile. Beatmatching is an imprecise science, the iterative art of aligning two tracks by ear in realtime. As mixes ebb and flow in and out of lock, the DJ corrects them with little nudges. These in turn produce transient flickers in the key of the riddim, a live reproduction reminiscent of grime producer Terror Danjah's pitchbent synths or Kode9's own off-dissonant, mystical melodies.

Though predominantly dubstep in selection, this mix is further informed by grime's rapid-fire DJ-ing style. A great deal of dubstep is built from linear instrumental tracks that both evolve iteratively to give a sense of progression and are designed fr precise and smooth beatmixing. By contrast in grime, where the propulsive momentum comes from the MC, riddims are often constructed in interlocking blocks of 8 or 16 similar bars. Consequently sharp switches or even gaps in sets are possible, just as long as the MC's bars continue to flow. DJs like Plasticman, NASTY Crew's Mac 10 or Roll Deep's Karnage have perfected a rapid-fire DJ style to capitalise on this.

The effect of this kind of mixing is also to mutate the boundaries of the tracks, so production and mix decisions are blurred. Repeated listens imprint the mixes in the listeners memory, so that when one of the 28 tracks is subsequently heard in a dance it leaves the listener also craving for the track it is mixed here with.

Kode9 also blurs the line between dubstep's predominantly instrumental nature and grime's focus on lyrics. During the first half of the mix, once dancehall MC Warrior Queen has vented her anger at London being bombed last year, Spaceape's vocals begin to dominate the mix. Unlike a grime MC however, there's no momentary turn through aggressive, percussive lyrical fury. It's far closer to dub poet Linton Kwesi Johnson in style, yet the spirit of frustration remains embedded in the lyrics. Spaceape questions social progress and gives bittersweet thanks for his own existence, despite a happy-go-lucky childhood.

By the second half of the mix Spaceape's voice becomes far more of an instrument, bouncing around different parts of the stereo spectrum, descending from different spaces and places, to complement rather than dominate the mix. Yet it remains a welcome addition, a reminder of the Anglo-Jamaican heritage that surrounds modern urban music and the voices of ghosts lost amidst dark electronic textures.